Many formulations such as inks, paints, mill-bases and plastics materials require effective dispersants for uniformly distributing a particulate solid in an organic medium. The organic medium may vary from a polar to non-polar organic medium. Consequently, dispersants are sought which can disperse a particulate solid in both a polar and a non-polar organic medium.
U.S. Pat. No. 4,224,212 discloses dispersants comprising a polyester derived from a hydroxycarboxylic acid with at least 8 carbon atoms reacted with a poly(loweralkylene)imine. The dispersants are effective in non-polar medium such as aliphatic solvents and plastics.
EP208041 discloses dispersants comprising a polyester derived from ε-caprolactone reacted with a poly(lower alkylene)imine. The dispersants are effective in more polar medium such as ketones and esters.
U.S. Pat. No. 4,865,621 discloses motor fuel compositions comprising the reaction product of a dibasic acid anhydride, a polyoxyalkylene monoamine and a hydrocarbyl polyamine having a number average molecular weight of up to 1343.